Accession Number:

AD0600173

Title:

ABLATION OF A SOLID SPHERE OF A LOW CONDUCTIVITY MATERIAL

Descriptive Note:

Corporate Author:

POLYTECHNIC INST OF BROOKLYN NY

Personal Author(s):

• Parisse, Richard F.

Report Date:

1964-04-01

Pagination or Media Count:

30.0

Abstract:

An approximate solution is presented for determining transient temperature distributions and ablation rates for solid spheres of low thermal conductivity and constant thermal properties, subjected to point symmetric aerodynamic heat inputs. A short time solution for the temperature which is valid prior to ablation, is developed by use of Laplace transforms. The ablation solution is derived by approximation of the radial temperature profile by an exponential function and utilization of the heat balance technique. This results in a second-order, nonlinear, ordinary differential equation for the position of the ablating surface. Results of the numerical integration of the approximate solutions are compared with experimental data obtained at the stagnation point of a Plexiglas hemisphere tested under hypersonic flow conditions. A discussion of the techniques employed, as well as the comparison with experimental data, appear in the body of the report.

Descriptors:

• *ABLATION
• *AERODYNAMIC HEATING
• *HEAT SHIELDS
• ACRYLIC RESINS
• COMPARISON
• CONDUCTIVITY
• DIFFERENTIAL EQUATIONS
• DISTRIBUTION
• EXPERIMENTAL DATA
• EXPONENTIAL FUNCTIONS
• HEAT BALANCE
• HEAT OF SUBLIMATION
• HEMISPHERES
• HYPERSONIC FLOW
• HYPERSONIC WIND TUNNELS
• INTEGRATION
• LAPLACE TRANSFORMATION
• MATERIALS
• PLEXIGLAS
• POSITION(LOCATION)
• PROFILES
• RATES
• REENTRY VEHICLES
• SHORT RANGE(TIME)
• SOLIDS
• SOLUTIONS(GENERAL)
• SPHERES
• STAGNATION POINT
• SURFACES
• SYMMETRY
• TEMPERATURE
• THERMAL CONDUCTIVITY
• THERMAL PROPERTIES
• TRANSIENTS
• UTILIZATION

Subject Categories:

• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE